Apparatus and method for registering visible light communication device and combining visible light communication signal and wireless communication signal

ABSTRACT

Disclosed are a method and apparatus for registering visible light communication devices and combining a visible light communication signal and a wireless communication signal. It is an object of the present disclosure to provide a visible light communication device registration method in which a lighting device allows collective registration of the lighting device and a terminal as the terminal transmits data to a light using wireless communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 15/939,767, filed onMar. 29, 2018 which is a continuation of International Application No.PCT/KR2016/010979, filed Sep. 30, 2016, which claims priority under 35U.S.C § 119(a) of Patent Application No. 10-2015-0137526, filed on Sep.30, 2015 in Korea, Patent Application No. 10-2016-0112431, filed on Sep.1, 2016 in Korea, and Patent Application No. 10-2016-0114371, filed onSep. 6, 2016 in Korea. The entire disclosures of each of the aboveapplications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a method and apparatus for registeringvisible light communication devices and combining a visible lightcommunication signal and a wireless communication signal.

BACKGROUND

The statements in this section merely provide background information onthe present disclosure and do not necessarily constitute the prior art.

Visible light communication is wireless communication technology fortransmitting visible light data, which is configured in an on/off signalpattern, using the fast response speed of a lighting device. For visiblelight communication, when the lighting device is given a visible lightcommunication function and installation position information about thelighting device is used, various communication supplementary servicesmay be provided. For example, a communication supplementary service maybe employed as a service for measuring the position of a terminal in aroom, and may also be employed as a service for transmitting informationfrom the lighting device to the terminal.

In order for visible light communication to provide various services asdescribed above, communication devices used for visible lightcommunication are required to be registered with a server. When aplurality of lighting devices is present, the lighting devices may beregistered with the server, and the server may classify and deliver datato the respective lighting devices. Further, when visible lightcommunication is used for a positioning service, the position of aterminal near the lighting device may be measured if the position of thelighting device has been registered. If the terminal has been registeredwith the server in advance, the server may determine whether theterminal requesting a specific service is a registered terminal toselectively provide the service.

According to the conventional visible light communication technology,the lighting device is capable of transmitting data to the terminal, butthe terminal is not allowed to transmit data to the lighting device.Therefore, in registering the lighting device and the terminal with theserver, the lighting device is required to be separately registered withthe server, and the terminal is also required to be directly andseparately registered with the server, which is inconvenient. As thenumber of terminals receiving data from the lighting device increases,the procedure of registration with the server becomes complex.

There is a case where a specific service is provided and the lightingdevice needs to receive data from the terminal. Thus, a wirelesscommunication module may be embedded in the lighting device. Then, thelighting device is enabled to transmit and receive data by wirelesscommunication while operating as a light source. The lighting devicereceives attribute information about a light from the terminal or IoT(Internet of Things) devices using the wireless communication module.IoT devices refer to all smart devices and sensors for which IoTtechnology-based services are intended. The attribute information aboutthe light is information on the brightness of the light, andconceptually includes luminosity, intensity of illumination, luminance,or dimming of the light. The lighting device may adjust the brightnessof the light according to the attribute information about the light.

A lighting device may implement the visible light communication functionusing an intrinsic attribute of the light. However, the conventionallighting device is required to be equipped with both a visible lightcommunication module and a wireless communication module to implementboth wireless communication and visible light communication. As aresult, the unit price of the lighting device is increased, and portsfor outputting the visible light communication signal and the wirelesscommunication signal, respectively, must be employed, which causesinconvenience.

In order to overcome such issues, a lighting device for processing avisible light communication signal and a wireless communication signalin a single module has been introduced. However, this lighting deviceselectively performs an operation of transmitting a visible lightcommunication signal as a light source and an operation of transmittinga wireless communication signal. Receiving lighting attributeinformation from an IoT device in real time requires a module forprocessing the wireless communication signal to continuously operate,but the conventional lighting device cannot operate as a light source inthis case.

SUMMARY

In accordance with some embodiments of the present disclosure, alighting device of visible light, to be registered together with aterminal with a server, comprises a communication unit configured tocommunicate with the server and the terminal. The lighting devicefurther comprises a controller configured to perform a control operationto modulate a terminal search signal into a visible light communicationsignal upon receiving a lighting search signal from the server via thecommunication unit, to transmit the visible light communication signalto the terminal and to transmit, upon receiving a terminal registrationsignal from the terminal via the communication unit, the terminalregistration signal and a lighting registration signal to the server,wherein the terminal registration signal comprises an identifier of theterminal and the lighting registration signal comprises an identifier ofthe lighting device. The lighting device still further comprises alighting part configured to modulate the terminal search signal into thevisible light communication signal under control of the controller andtransmit the visible light communication signal to the terminal.

In accordance with some embodiments of the present disclosure, aterminal device, to be registered with a lighting device, comprises avisible light receiver configured to receive, from the lighting device,a terminal search signal transmitted as a visible light communicationsignal, using a visible light receiving module. The terminal devicefurther comprises a controller configured to control, when the visiblelight receiver demodulates the received visible light communicationsignal and recognizes reception of the terminal search signal, aterminal registration signal containing an identifier of the terminal tothe lighting device. The terminal device still further comprises acommunication unit configured to transmit the terminal registrationsignal to the lighting device under control of the controller.

In accordance with some embodiments of the present disclosure, a visiblelight communication server, for managing registration of a lightingdevice and a terminal, comprises a communication unit configured totransmit a lighting search signal to the lighting device and receive,from the lighting device, a lighting registration signal containing anidentifier of at least one lighting device and a terminal registrationsignal containing an identifier of at least one terminal. The visiblelight communication server further comprises an identifier managementunit configured to manage the identifiers of the respective lightingdevices and the identifiers of the terminals received by thecommunication unit so as to be distinguished from each other and stored.The visible light communication server still further comprises adatabase configured to store the identifiers of the respective lightingdevices and the identifiers of the terminals received by thecommunication unit under control of the identifier management unit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a visible light communication systemaccording to an embodiment of the present disclosure.

FIG. 2 is a block diagram of a server according to an embodiment of thepresent disclosure.

FIG. 3 is a block diagram of a lighting device according to anembodiment of the present disclosure.

FIG. 4 is a block diagram of a terminal according to an embodiment ofthe present disclosure.

FIG. 5 is a timing chart illustrating a process of registering a visiblelight communication device with a server according to an embodiment ofthe present disclosure.

FIG. 6 is a timing chart illustrating a process of registering a visiblelight communication device with a server according to an embodiment ofthe present disclosure.

FIG. 7 is a flowchart illustrating an operation of a lighting deviceaccording to an embodiment of the present disclosure.

FIG. 8 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

FIG. 9 is a diagram illustrating a visible light communication systemaccording to another embodiment of the present disclosure.

FIG. 10 is a block diagram of a lighting device according to anotherembodiment of the present disclosure.

FIG. 11 is a block diagram of a terminal according to another embodimentof the present disclosure.

FIG. 12 is a flowchart illustrating a method for performingcommissioning by a lighting device according to another embodiment ofthe present disclosure.

FIG. 13 is a flowchart illustrating a method for performingcommissioning by a terminal according to another embodiment of thepresent disclosure.

FIG. 14 is a diagram illustrating a visible light communication systemaccording to yet another embodiment of the present disclosure.

FIG. 15 is a block diagram of a lighting device according to yet anotherembodiment of the present disclosure.

FIG. 16(a) is a graph depicting a waveform of a signal radiated from aconventional lighting device.

FIG. 16(b) is a graph depicting a waveform of a signal radiated from alighting device according to yet another embodiment of the presentdisclosure.

FIG. 17 is a block diagram of a terminal according to yet anotherembodiment of the present disclosure.

FIG. 18 is a timing chart illustrating a process of pairing a lightingdevice and a terminal according to yet another embodiment of the presentdisclosure.

FIG. 19 is a flowchart illustrating an operation of a lighting deviceaccording to yet another embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, at least one embodiment of the present disclosure will bedescribed in detail with reference to the accompanying drawings. In thefollowing description, like reference numerals designate like elements,although the elements are shown in different drawings. Further, in thefollowing description of the at least one embodiment, a detaileddescription of known functions and configurations incorporated hereinwill be omitted for the purpose of clarity and for brevity.

Additionally, various terms such as first, second, A, B, (a), (b), etc.,are used solely for the purpose of differentiating one component fromthe other but not to imply or suggest the substances, the order orsequence of the components. Throughout this specification, when a part“includes” or “comprises” a component, the part is meant to furtherinclude other components, not excluding thereof unless there is aparticular description contrary thereto. The terms such as “unit”,“module”, and the like refer to units for processing at least onefunction or operation, which may be implemented by hardware, software,or a combination thereof.

It is an object of the present disclosure to provide a visible lightcommunication device registration method in which a lighting deviceallows collective registration of the lighting device and a terminal asthe terminal transmits data to a light using wireless communication.

It is another object of the present disclosure to provide a method andapparatus for enabling a visible light communication service to beprovided more efficiently by selectively transmitting an identifier of alighting device in a visible light communication process such that aposition registration procedure for the lighting device is automaticallyperformed based on the identifier.

It is yet another object of the present disclosure to provide a methodfor combining a visible light communication signal and a wirelesscommunication signal to allow a lighting device to perform visible lightcommunication while performing wireless communication in real time.

It is yet another object of the present disclosure to provide a methodfor combining two signals having different speeds without causingflicker.

FIG. 1 is a diagram illustrating a visible light communication systemaccording to an embodiment of the present disclosure.

The visible light communication system 100 includes a server 110, alighting device 120, and a terminal 130.

The server 110 is a management device of the visible light communicationsystem that is configured to receive and register an identifier from thelighting device 120 or the terminal 130 and determine whether to allow avisible light communication service depending on the registration.

The server 110 receives and registers the identifiers of the individuallighting devices 120 and the terminal 130 individually. The server 110is connected to the lighting device 120 over a wired or wirelessnetwork. The wired network refers to communication technology fortransmitting information to a remote place by a wired connection usingradio waves. Examples of this technology include Ethernet communication,universal serial bus (USB), and wired communication using a wire, atwisted pair of wires, a coaxial cable, an optical link, or the like.The wireless network refers to a communication technology fortransmitting information to a remote place using radio waves withoutconnection by wire. Examples of this technology include Bluetooth, RFID(Radio Frequency Identification), IrDA (Infrared Data Association), UWB(Ultra-Wide Band), ZigBee, DLNA (Digital Living Network Alliance), WLAN(Wireless LAN), Wi-Fi, WiBro (Wireless broadband), WIMAX (WorldInteroperability for Microwave Access), HSDPA (High Speed DownlinkPacket Access), LTE/LTE-A (Long Term Evolution/LTE-Advanced), and thelike. The server 110 may distinguish the lighting device from theterminal using the identifiers.

There may be lighting devices connected to the server 110 over a wiredor wireless network or attempting to connect but not yet registered withthe server 110. To discover these lighting devices and guideregistration thereof, the server 110 transmits a lighting search signalto the lighting devices connected thereto. The server 110 may transmit alighting search signal when the number of unregistered lighting devicesis greater than or equal to a preset reference value or may periodicallytransmit the lighting search signal regardless of the number of lightingdevices. The server 110 registers and stores each lighting device byreceiving a light registration signal containing an identifier of thelighting device from the lighting device.

The server 110 may receive, from the terminal 130, service informationthat the terminal desires to use. The service information refers toinformation about a visible light communication service that theterminal desires to use among various visible light communicationservices. Upon receiving the service information from the terminal 130,the server 110 assigns a service identifier corresponding to the serviceinformation. The service identifier is stored in the server 110 togetherwith the identifier of the terminal.

The lighting device 120 serves to convert data received from the server110 into a visible light communication signal and to transmit theconverted signal to the terminal. The lighting device 120 generates avisible light communication signal by repeatedly turning on or off. Theterm “visible light communication” refers to a technique fortransmitting information using light in the visible light wavelengthrange that is recognizable by the eyes. Since the lighting device 120repeats turning on or off at a speed that the human optic nerve cannotrecognize, it may transmit data while maintaining the function oflighting. The lighting device 120 may be implemented using a lightemitting diode (LED), but is not limited thereto. Any device that emitsvisible light such as fluorescent light or visible light laser may beused.

The lighting device 120 includes a wired or wireless communicationmodule. The lighting device 120 uses a wired or wireless communicationmethod for the server 110 and uses a wireless communication method forthe terminal 130.

The lighting device 120 transmits data to the terminal using a visiblelight communication method. The lighting device 120 may receive alighting search signal from the server 110. Upon receiving the lightingsearch signal, the lighting device 120 may transmit an identifierthereof directly to the server 110. However, embodiments are notnecessarily limited thereto, and the following operation may beperformed. When the lighting device 120 receives the lighting searchsignal from the server 110, it transmits a terminal search signal tocheck whether there is a terminal that is not registered with the server110. In transmitting the terminal search signal to a terminal, thelighting device 120 does not specify a terminal, but allows allterminals in the area reached by the visible light of the lightingdevice 120 to receive the signal. Although FIG. 1 illustrates that thereis only one terminal 130, a plurality of terminals 130 is common.

The lighting device 120 receives a terminal registration signal from theterminal 130. The lighting device 120 receives, from the server 110, aterminal identifier registered with the server 110 in advance and acorrespondingly stored service identifier, and stores the receivedidentifiers. The lighting device 120 compares the terminal identifierreceived from the terminal with a pre-stored terminal identifier anddetermines whether to transmit the service identifier to the server 110depending on the result of comparison. A detailed description will begiven with reference to FIG. 6 or 7.

The terminal 130 is a device configured to receive a visible lightcommunication signal from the lighting device 120, demodulate thereceived visible light communication signal to extract data and transmitthe data to the lighting device 120 using the wireless communicationmethod. The terminal 130 may be implemented as an Internet of Things(IOT) device including a light receiving sensor as well as a smartdevice such as a smartphone or a tablet PC, a notebook, a laptop, and apersonal digital assistant (PDA). The terminal 130 receives the visiblelight communication signal from the lighting device 120 and converts thesame into an electrical signal. The lighting device includes a built-inor external visible light receiving module. The visible light receivingmodule may be implemented as a camera, a photodiode, or the like, but isnot limited thereto. Any module capable of receiving visible light isacceptable.

The terminal 130 receives a terminal search signal from the lightingdevice 120 and transmits a terminal registration signal including theterminal identifier to the lighting device 120.

The terminal 130 may transmit the terminal identifier and the serviceinformation to be used to the server 110 upon or before transmitting theterminal registration signal.

A lighting device identifier or a terminal identifier refers toinformation by which the lighting device or terminal may be identified.A unique production number or the like assigned at the time ofproduction of the lighting device or the terminal may be used as anidentifier. Unique identification information such as, for example, aMAC address, may be used as an identifier on the network that thelighting device or the terminal uses. The above-described information ismerely an example of an identifier, and any information by which thelighting device or each terminal may be identified may be used as anidentifier.

FIG. 2 is a block diagram of a server according to an embodiment of thepresent disclosure.

The server 110 includes a communication unit 210, an identifiermanagement unit 220, and a database 230.

The communication unit 210 transmits the lighting search signal to thelighting device 120. In transmitting the lighting search signal to thelighting device 120, the communication unit 210 may transmit theterminal identifier or the service identifier received from the terminal130 as well.

The communication unit 210 receives a light registration signalincluding the lighting device identifier and a terminal registrationsignal including the terminal identifier from the lighting device 120.The communication unit 210 may be implemented as a wired or wirelesscommunication module depending on the type of connection with thelighting device 120 and the terminal 130. The communication unit 210 mayreceive a service identifier together with the light registration signaland the terminal registration signal.

Before transmitting the lighting search signal to the lighting device120, the communication unit 210 may receive the terminal identifier andthe service information from the terminal 130.

The identifier management unit 220 receives the lighting deviceidentifier or the terminal identifier from the communication unit 210,and manages the identifiers so as to be distinguished from each otherand stored in the database 230. While FIG. 1 illustrates that there isone lighting device 120 and one terminal 130, there may be a pluralityof lighting devices 120 and a plurality of terminals 130. Since thelighting device identifier and the terminal identifier may besimultaneously or sequentially received from the respective lightingdevices and terminals, the identifier management unit 220 distinguisheseach of the identifiers and stores the same in the database 230.

When the identifier management unit 220 receives the terminal identifierand the service information from the communication unit 210, it assignsa service identifier corresponding to the service information. Afterassigning the service identifier, the identifier management unit 220stores the same together with the terminal identifier in the database230. By storing the service identifier and the terminal identifiertogether, the server 110 may determine whether a specific terminal canuse a specific service. For example, suppose that a visible lightpositioning service identifier is matched with terminal A and stored.Upon receiving the identifier of terminal A, the server 110 maydetermine terminal A as a terminal that can use the visible lightpositioning service. On the other hand, when the server 110 receives aterminal identifier of a terminal other than terminal A, the server 110may determine the terminal as a terminal that cannot use the visiblelight positioning service.

Under control of the identifier management unit 220, the database 230stores the identifiers of the lighting devices or terminals received bythe communication unit 210. When the identifier management unit 220assigns service identifiers according to the terminal identifiers, thedatabase 230 may store the service identifiers by matching the same withthe terminal identifiers.

FIG. 3 is a block diagram of a lighting device according to anembodiment of the present disclosure.

The lighting device 120 includes a communication unit 310, a controller320, an identifier storage unit 330, and a lighting part 340.

The communication unit 310 receives a lighting search signal from theserver 110. The communication unit 310 may be connected to the server110 using a wired/wireless communication module and receive the lightingsearch signal from the server 110. The communication unit 310 mayreceive a terminal identifier and a service identifier pre-registeredwith the server 110, together with the lighting search signal.

The communication unit 310 receives a terminal registration signalincluding a terminal identifier from the terminal 130. The communicationunit 310 is connected to the terminal 130 using the wirelesscommunication module and receives the terminal registration signal fromthe terminal 130. After receiving the terminal registration signal fromthe terminal 130, the communication unit 310 transmits the lightingregistration signal including the lighting device identifier and theterminal registration signal to the server 110. In some cases, thecommunication unit 310 may transmit the service identifier received fromthe terminal together with the lighting registration signal and theterminal registration signal.

When the lighting search signal is received from the server 110, thecontroller 320 controls the lighting part 340 to transmit a terminalsearch signal using the visible light communication signal. When thecommunication unit 310 receives the lighting search signal, thecontroller 320 generates a visible light communication signal bymodulating the terminal search signal for searching for a terminalthrough pulse modulation, frequency shift keying (FSK), phase shiftkeying (PSK), on-off keying (OOK), or the like. Pulse modulation is atechnique of sampling a waveform at discrete time intervals andperforming modulation by changing the amplitude, phase (position), widthor the like of a pulse train generated according to the sampling. Pulsemodulation is divided into pulse amplitude modulation (PAM), pulse widthmodulation (PWM), and pulse position modulation (PPM). FSK and PSK aremethods of transmitting digital information by using changes in discretefrequency and phase of a carrier wave. OOK is a modulation method ofdisplaying digital data depending on presence or absence of a carrierwave. OOK is a method of displaying binary value 1 when there is acarrier transmitted at a specific time, and displaying binary value 0when there is no carrier transmitted at the specific time. Thecontroller 320 controls the lighting part 340 to transmit the generatedterminal search signal on the visible light communication signal. Whenthe terminal identifier and the service identifier pre-registered withthe server 110 are received together with the lighting search signal,the controller 320 stores the pre-registered terminal identifier andservice identifier in the identifier storage unit 330.

In controlling transmission of the terminal search signal, thecontroller 320 may add information for adjusting the transmission timingof the terminal registration signal to the terminal search signalaccording to the terminal identifier. For example, suppose that theterminal identifier is implemented as a number. When the last digit ofthe terminal identifier is between 1 and 5, the controller 320 may addcontrol information causing the terminal to transmit a terminalregistration signal as soon as the terminal receives the terminal searchsignal. On the other hand, when the last digit is between 6 and 9, thecontroller 320 may add control information causing the terminal totransmit the terminal registration signal a predetermined time afterreceiving the terminal search signal. In this way, by adjusting thetransmission timing of the terminal registration signal according to theterminal identifier, the controller 320 may prevent the lighting device120 from being overloaded when the number of terminals transmittingterminal registration signals to the lighting device 120 increases.

When a terminal registration signal is received from the terminal 130,the controller 320 analyzes the terminal identifier included in theterminal registration signal. The controller 320 compares the terminalidentifier received from the terminal 130 with a pre-registered terminalidentifier stored in the identifier storage unit 330 and determineswhether or not the terminal identifiers coincide with each other. If thetwo terminal identifiers do not coincide with each other, the controller320 may recognize that the terminal 130 is not a terminal desiring touse a specific visible light communication service. If the two terminalidentifiers coincide with each other, the controller 320 determineswhether a service identifier corresponding to the terminal identifier ispresent in the identifier storage unit 330. If the service identifier ispresent in the identifier storage unit 330, the controller 320 mayrecognize that the terminal 130 is a terminal desiring to use thespecific visible light communication service.

The controller 320 determines whether to transmit the service identifierdepending on the result of the analysis. When the controller 320recognizes that the terminal 130 is not a terminal desiring to use thespecific visible light communication service, the controller controlsthe communication unit 310 to transmit only the lighting registrationsignal including the identifier of the lighting device 120 and theterminal registration signal including the terminal identifier to theserver 110. Upon receiving the lighting registration signal and theterminal registration signal, the server 110 may recognize that theterminal is not a terminal desiring to use the specific visible lightcommunication service, and may limit the specific visible lightcommunication service for the terminal. On the other hand, when thecontroller 320 recognizes that the terminal 130 is a terminal desiringto use the specific visible light communication service, the controller320 controls the communication unit 310 to transmit a service identifiertogether with the lighting registration signal and the terminalregistration signal to the server 110. Since the server 110 receives theservice identifier together with the lighting registration signal andthe terminal registration signal, it may allow the terminal to use thespecific visible light communication service.

The identifier storage unit 330 stores the pre-registered terminalidentifier and service identifier received together with the lightingsearch signal.

The lighting part 340 transmits the terminal search signal using avisible light communication signal under control of the controller 320.The lighting part 340 does not specify a terminal in transmitting theterminal search signal, but transmits the terminal search signal to allterminals within the range of the visible light communication signal ofthe lighting part 340.

FIG. 4 is a block diagram of a terminal according to an embodiment ofthe present disclosure.

The terminal 130 includes a communication unit 410, a visible lightreceiver 415, a controller 420, an identifier storage unit 430, and atimer 440.

The communication unit 410 may directly transmit a terminal identifierand service information to the server 110. The communication unit 410may include a wireless communication module and may transmit the serviceinformation together with the terminal identifier to the server 110.

The communication unit 410 receives a service identifier from the server110. The received service identifier is stored in the identifier storageunit 430.

The communication unit 410 transmits a terminal registration signalincluding the terminal identifier and a service identifier to thelighting device 120 according to the result of determination of thecontroller 420.

The visible light receiver 415 receives the terminal search signal andthe service identifier from the lighting device 120. The visible lightreceiver 415 may receive the terminal search signal transmitted over thevisible light communication signal using the visible light receivingmodule. After receiving the visible light communication signal, thevisible light receiver 415 converts the same into an electrical signal.At this time, control information for adjusting the transmission timingof the terminal registration signal may be included in the terminalsearch signal.

The controller 420 determines whether the service identifier receivedfrom the server 110 and stored in the identifier storage unit 430coincides with the service identifier received from the lighting device120. The controller 420 demodulates the electrical signal obtainedthrough conversion in the visible light receiver 415, using the sametechnique as the modulation method performed by the lighting device 120.By performing demodulation, the controller 420 recognizes that theterminal search signal has been received from the lighting device 120.In order to determine whether the service requested by the controller420 coincides with the service that the lighting device 120 intends tocheck, the controller 420 determines whether the identifiers of bothservices coincide with each other.

The controller 420 transmits a terminal registration signal or theterminal registration signal and a service identifier depending on theresult of the determination. If the service identifier stored in theidentifier storage unit 430 does not coincide with the serviceidentifier received from the lighting device 120, the controller 420transmits a terminal registration signal including the terminalidentifier to the lighting device 120. On the other hand, if the serviceidentifiers coincide with each other, the controller 420 transmits theservice identifier together with the terminal identifier to the lightingdevice 120. If the two service identifiers coincide with each other, thecontroller 420 controls the terminal 130 to transmit, to the lightingdevice 120, the service identifier together with the terminalregistration signal including the terminal identifier in order toannounce that the terminal 130 is a terminal that can use thecorresponding service. When control information for adjusting thetransmission timing of the terminal registration signal is included inthe terminal search signal, the controller 420 adjusts the terminalregistration signal transmission timing of the communication unit 410according to the control information.

The identifier storage unit 430 stores the service identifier receivedfrom the server 110.

The timer 440 checks the timing to transmit the terminal registrationsignal according to the control information for adjusting thetransmission timing of the terminal registration signal.

FIG. 5 is a timing chart illustrating a process of registering a visiblelight communication device with a server according to an embodiment ofthe present disclosure.

The server 110 transmits a lighting search signal to the lighting device120 (S510). The server 110 may transmit, to the lighting device 120, thelighting search signal including control information for adjusting thetransmission timing of the terminal registration signal.

Upon receiving the lighting search signal from the server 110, thelighting device 120 transmits a terminal search signal to the terminal130 (S520). The lighting device 120 modulates the terminal search signalinto a visible light communication signal through pulse modulation,shift keying, or OOK and transmits the visible light communicationsignal. The lighting device 120 omnidirectionally transmits the lightingsearch signal to all the terminals within the range of the visible lightcommunication signal.

Upon receiving the terminal search signal, the terminal 130 transmits aterminal registration signal to the lighting device 120 (S530). When theterminal search signal is received using the visible light receiver, theterminal 130 converts the visible light communication signal into anelectrical signal and demodulates the electrical signal using the sametechnique as the modulation method used by the lighting device 120. Byperforming demodulation, the controller 420 recognizes that the terminalsearch signal has been received from the lighting device 120. Afterrecognizing receipt of the terminal search signal, the terminal 130transmits a terminal registration signal including the terminalidentifier to the lighting device 120. The terminal 130 transmits theterminal registration signal including the terminal identifier to thelighting device 120 using wireless communication.

Upon receiving the terminal registration signal, the lighting device 120transmits the terminal registration signal and the lighting registrationsignal to the server 110 (S540). The lighting device 120 transmits, tothe server 110, a lighting registration signal including the identifierthereof together with the terminal registration signal received from theterminal 130.

The server 110 registers the lighting device 120 and the terminal 130(S550). While the lighting device 120 is illustrated in FIG. 5 asreceiving a terminal registration signal from one terminal, it mayreceive terminal registration signals from a plurality of terminals. Asthe lighting device 120 transmits, to the server 110, the identifierthereof and all the received identifiers of a plurality of terminalsconnected thereto through visible light communication, the server 110may simultaneously receive and register the identifiers from thelighting device 120 without receiving the lighting device identifier andterminal identifiers individually from the lighting device 120 and theplurality of terminals and receiving corresponding registrationrequests.

FIG. 6 is a timing chart illustrating a process of registering a visiblelight communication device with a server according to an embodiment ofthe present disclosure.

The terminal 130 directly transmits the terminal identifier and serviceinformation to the server 110 (S610). The terminal 130 transmits theterminal identifier and service information in advance beforeregistering with the server 110.

The server 110 assigns a service identifier and stores the same togetherwith the terminal identifier (S615). Upon receiving the serviceinformation together with the terminal identifier from the terminal 130,the server 110 assigns a unique service identifier corresponding to theservice information. The server 110 may register the terminal as aterminal that can use a specific service in advance.

The server 110 transmits the service identifier to the terminal 130(S620).

The terminal 130 stores the received service identifier (S625).

The server 110 transmits the lighting search signal, the terminalidentifier, and the service identifier to the lighting device 120(S630). In transmitting the lighting search signal, the server 110 mayadd, to the lighting search signal, control information for adjustingthe transmission timing of a terminal registration signal.

The lighting device 120 stores the terminal identifier and the serviceidentifier (S635).

The lighting device 120 transmits the terminal search signal and theservice identifier to the terminal 130 (S640). When the lighting device120 receives a lighting search signal and a service identifier from theserver 110, the lighting device 120 modulates the terminal search signaland the service identifier into a visible light communication signalusing pulse modulation, shift keying, or OOK and transmits the visiblelight communication signal. The lighting device 120 may transmit, to theterminal 130, the terminal search signal including control informationfor adjusting the transmission timing of the terminal registrationsignal.

The terminal 130 determines whether the received service identifiercoincides with the stored service identifier (S645). By determiningwhether the service identifiers coincide with each other, the terminal130 determines whether the service for which a request has been made tothe server 110 coincides with the service that the lighting device 120intends to check.

If both service identifiers coincide with each other, the terminal 130transmits the terminal registration signal and the service identifier tothe lighting device 120 (S650). By transmitting the service identifiertogether with the terminal registration signal including the terminalidentifier, the terminal 130 indirectly informs the server 110 that theservice requested by the terminal coincides with the service that thelighting device 120 intends to check.

The lighting device 120 determines whether the terminal identifierreceived from the terminal 130 coincides with the stored terminalidentifier (S655). If the two terminal identifiers do not coincide witheach other, the lighting device 120 may recognize that the terminal 130is not a terminal desiring to use a specific visible light communicationservice.

If the two terminal identifiers coincide with each other, the lightingdevice 120 determines whether a service identifier corresponding to thereceived terminal identifier is present (S660). If the two terminalidentifiers coincide with each other, the lighting device 120 determinesonce again whether there is a service identifier corresponding to thereceived terminal identifier among the stored service identifiers. Ifthere is a coincident service identifier, the lighting device 120 mayrecognize that the terminal 130 is a terminal desiring to use thespecific visible light communication service.

If the two terminal identifiers do not coincide with each other or thereis no service identifier corresponding to the received terminalidentifier, the lighting device 120 transmits a lighting registrationsignal to the server (S665). As the server 110 receives the lightingregistration signal alone, it may recognize that the terminal is not aterminal to use a specific visible light communication service, andlimit specific visible light communication services for the terminal.

If the two terminal identifiers do coincide with each other and there isa service identifier corresponding to the received terminal identifier,the lighting device 120 transmits a lighting registration signal, aterminal registration signal, and the service identifier (S670).

The server 110 registers the lighting device 120, or checks the positionof the terminal 130, registering the lighting device 120 (S675). If thelighting registration signal is received alone in operation S665, theserver 110 registers the lighting device 120. Upon receiving thelighting registration signal, the terminal registration signal, and theservice identifier in operation S670, the server 110 registers thelighting device and checks the terminal identifier and the serviceidentifier included in the terminal registration signal. Since theterminal identifier is a pre-registered terminal identifier, the server110 does not perform separate registration, but determine the currentposition of a lighting device positioned near a specific terminal thatcan use a specific service.

FIG. 7 is a flowchart illustrating an operation of a lighting deviceaccording to an embodiment of the present disclosure.

The terminal identifier and the service identifier are received from theserver 110 together with the lighting search signal (S710). The lightingdevice 120 receives the terminal identifier and the service identifiertogether with the lighting search signal from the server 110 using awired or wireless communication module.

The terminal identifier and the service identifier are stored (S720).

A terminal search signal is transmitted to the terminal 130 (S730). Thelighting device 120 transmits the terminal search signal using a visiblelight communication signal. Upon receiving the lighting search signaland the service identifier from the server 110, the lighting device 120modulates the terminal search signal into a visible light communicationsignal through pulse modulation, shift keying, or OOK, and transmits thevisible light communication signal. The lighting device 120 does notspecify a terminal in transmitting the terminal search signal, buttransmits the terminal search signal to all terminals within the rangeof the visible light communication signal of the lighting device 120.

A terminal registration signal including the terminal identifier isreceived (S740).

It is determined whether the stored terminal identifier coincides withthe received terminal identifier (S750). If the two terminal identifiersdo not coincide with each other, the lighting device 120 may recognizethat the terminal 130 is not a terminal desiring to use a specificvisible light communication service.

If the two terminal identifiers coincide with each other, it isdetermined whether there is a service identifier corresponding to thereceived terminal identifier among the stored service identifiers(S760). If the two identifiers coincide with each other and there is aservice identifier corresponding to the received terminal identifier,the lighting device 120 may recognize that the terminal 130 is aterminal desiring to use the specific visible light communicationservice.

If the two identifiers coincide with each other and there is a serviceidentifier corresponding to the terminal identifier received from theterminal 130, a lighting registration signal including the identifier ofthe lighting device 120, a terminal registration signal including theterminal identifier, and the service identifier are transmitted to theserver 110 (S770).

If the two identifiers do not coincide with each other or there is noservice identifier corresponding to the terminal identifier receivedfrom the terminal 130, a lighting registration signal including theidentifier of the lighting device 120 is transmitted to the server 110(S780).

FIG. 8 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

The terminal identifier and service information are transmitted to theserver 110 (S810). The communication unit 440 may transmit the terminalidentifier and the service information to the server 110 using wirelesscommunication.

The service identifier corresponding to the terminal identifier isreceived from the server 110 (S820).

The service identifier received from the server 110 is stored (S830).

The service identifier and the terminal search signal are received fromthe lighting device 120 (S840). The terminal 130 may include a visiblelight receiving module and receives a service identifier and a terminalsearch signal from the lighting device 120 using a visible lightcommunication signal. Upon receiving the terminal search signal from thelighting device 120, the terminal 130 demodulates the terminal searchsignal using the same technique as the method of modulation performed bythe lighting device 120. By performing the demodulation, the controller420 recognizes that the terminal search signal has been received fromthe lighting device 120.

It is determined whether the stored service identifier coincides withthe received service identifier (S850). The terminal 130 determineswhether the service requested by the terminal coincides with the servicethat the lighting device 120 intends to check by determining whether thetwo service identifiers coincide with each other.

If the two service identifiers coincide with each other, a terminalregistration signal including the terminal identifier and the serviceidentifier are transmitted to the lighting device 120 (S860).

FIG. 9 is a diagram illustrating a visible light communication systemaccording to another embodiment of the present disclosure.

The visible light communication system 900 includes a lighting device910, a terminal 920, and a server 930.

The lighting device 910 is a device that transmits data to the terminal920 over light in the visible light wavelength region. When the terminal920 is recognized in a visible light communication area, the lightingdevice 910 transmits an optical signal including data to the terminal920 based on visible light communication. A plurality of lightingdevices 910 is preferably provided in a preset lighting area, butembodiments are not limited thereto.

The lighting device 910 may include a communication module and may forma network together with other lighting devices, the server 930 and theterminal 920 in the preset lighting area using the communication moduleprovided thereto. The lighting device 910 may be operatively connectedwith other lighting devices, the server 930 and the terminal 920 usingthe network, and may receive visible light communication data from theserver 930. The network may be a wired or wireless network. The wirednetwork refers to a communication technology for transmittinginformation to a remote place by a wired connection using radio waves,and the wireless network refers to a communication technology fortransmitting information to a remote place using radio waves withoutconnection by wires. The visible light communication data may includevarious kinds of information such as multimedia information, such asvoice, images and videos, and control information for controlling thelighting device 910.

The lighting device 910 may selectively transmit the lighting deviceidentifier to the terminal 920 together with the visible lightcommunication data in the process of visible light communication withthe terminal 920. The lighting device 910 may use the uniqueidentification information about the wireless communication moduleprovided in the lighting device 910 as the lighting device identifier.When the communication module is a wireless communication module, thecommunication module has a unique hardware address. For example, whenthe communication module is a ZigBee wireless communication module, thecommunication module has a unique address having a length of 8 bytes.Considering this point, the communication module may use a uniquehardware address as the lighting device identifier.

The lighting device 910 selectively transmits the lighting deviceidentifier to the terminal 920 together with the visible lightcommunication data depending on whether the position of the lightingdevice 910 is registered with the server 930. The lighting deviceidentifier is used as a basis of the terminal 920 determining whether toperform the position registration procedure for the lighting device 910.The lighting device identifier is used as a basis of distinguishing thelighting device 910 from other lighting devices in the process ofregistering the position information about the lighting device 910.

The lighting device 910 may receive position information from theterminal 920 and transmit the same to the server 930.

The terminal 920 is a device for providing a visible light communicationservice to a user located in a preset lighting area by utilizing visiblelight communication.

The terminal 920 receives an optical signal from the lighting device 910installed in the preset lighting area, and extracts visible lightcommunication data from the optical signal.

The terminal 920 selectively calculates and provides the positioninformation about the lighting device 910 based on the relatedinformation about the lighting device 910 included in the visible lightcommunication data. The terminal 920 determines whether or not theposition of the lighting device 910 is registered based on the relatedinformation about the lighting device 910, and performs the procedure ofregistering the position of the lighting device 910 according to theresult of determination. Here, the related information about thelighting device 910 may contain only the lighting device identifier ormay contain the lighting device identifier and information about whetheror not the lighting device 910 is registered. A method for the terminal920 to determine whether or not the position of the lighting device 910is registered based on the related information about the lighting device910 will be described in detail with reference to FIG. 11.

Hereinafter, a method for the terminal 920 to perform a procedure ofregistering the position of the lighting device 910 will be described.

The terminal 920 calculates information of current position at which theterminal is located. In this operation, the terminal 920 calculates thecurrent position information about the terminal 920 using a part or theentirety of the GPS sensor and the motion sensor provided in theterminal 920.

The terminal 920 generates matching information by matching the lightingdevice identifier included in the related information about the lightingdevice 910 and the pre-calculated current position information about theterminal 920. Then, the terminal 920 provides the matching informationas the position information about the lighting device 910 to thelighting device 910 or the server 930.

In the case of configuring a lighting control system, the conventionalvisible light communication system causes inconvenience in theconfiguration phase as it requires the installation position of thevisible light lighting device in the visible light communication systemto be directly checked on site or requires the installation position ofthe lighting device to be checked by intentionally performing the on/offoperation of the visible light lighting device after installation.According to this embodiment, even if the user simply carries theterminal 920 in a certain pattern within a preset lighting area, theserver 930 may easily acquire the position information about thelighting device 910 included in the visible light communication system.

The server 930 performs control and monitoring operations on thelighting device 910 provided in the visible light communication system900. The server 930 updates the visible light communication data in thelighting device 910 using a network formed between the server 930 andthe lighting device 910.

In transmitting the visible light communication data to the lightingdevice 910, the server 930 may transmit the related information aboutthe lighting device 910 currently in operative connection with theserver 930 along with the visible light communication data. Thus, thelighting device 910 and the terminal 920 may selectively perform theprocedure of registering the position of the lighting device 910.

When the server 930 receives the position information about the lightingdevice 910 from the lighting device 910 or the terminal 920, itregisters the same as related information about the lighting device 910.Thereafter, the server 930 performs control and monitoring of thelighting device 910 based on the related information about the lightingdevice 910.

FIG. 10 is a block diagram of a lighting device according to anotherembodiment of the present disclosure.

The lighting device 910 includes a communication unit 1010, a controller1020, a driving unit 1030, a lighting part 1040, and a power conversionunit 1050.

The communication unit 1010 includes a communication module and receivesvisible light communication data from the terminal 920 or the server 930using the communication module. The communication unit 1010 receives thevisible light communication data from the server 930. The visible lightcommunication data includes information about registration of thelighting device 910 in the server 930. The communication unit 1010 mayreceive matching information obtained by matching the current positioninformation about the terminal 920 with the information about thelighting device.

The communication unit 1010 may receive the matching information fromthe terminal 920 and transmit the same to the server 930.

The controller 1020 generates a lighting control signal based on thevisible light communication data so as to generate a visible lightsignal corresponding to the received visible light communication data.

The controller 1020 checks if the position of the lighting device 910 isregistered in the server 930, and generates a lighting control signalbased on the lighting device identifier and the visible lightcommunication data according to the result of the checking. In thisoperation, the controller 1020 checks if the position of the lightingdevice 910 is registered in the server 930 based on the registrationinformation about the lighting device 910 included in the visible lightcommunication data. If it is determined as a result of the checking thata position registration procedure for the lighting device 910 is needed,the controller 1020 performs a control operation to transmit the visiblelight communication data including the lighting device identifier to theterminal 920.

Information about whether or not the lighting type informationcorresponding to the lighting device 910 is registered may be furtherincluded in the registration information about the lighting device 910.The lighting type information includes information at least one of thebrightness and color of the lighting unit. In this case, the controller1020 checks whether or not the lighting type information correspondingto the lighting device 910 is registered in the server 930 based on theregistration information about the lighting device 910, and generate alighting control signal, additionally considering the lighting typeinformation according to the result of the checking.

The driving unit 1030 turns the lighting unit included in the lightingpart 1040 on or off based on the generated lighting control signal. Thedriving unit 1030 may include a switching device for turning thelighting unit included in the lighting part 1040 on or off.

The lighting part 1040 includes a lighting unit composed of at least onelight emitting element. Here, the light emitting element is preferably alight emitting diode (LED), but is not limited thereto. For example, thelight emitting element may be implemented as an organic light emittingdiode (OLED) or a plasma light system (PLS). The lighting unit is turnedon or off by the driving unit 1030 to generate a visible light signalcorresponding to the visible light communication data. The method ofgenerating a visible light signal in accordance with the on or offoperation of the lighting unit is a typical technique in the field ofvisible light communication, and a detailed description thereof will beomitted.

The power conversion interval 1050 provides necessary power for drivingthe lighting device 910. For example, the power conversion unit 1050supplies DC power needed to drive the lighting unit in the lighting part1040.

FIG. 11 is a block diagram of a terminal according to another embodimentof the present disclosure.

The terminal 920 includes a receiver 1110, an extractor 1120, acontroller 1130, a position information calculator 1140, a display unit1150, a communication unit 1160, and a power source unit 1170.

The receiver 1110 receives visible light signals from at least onelighting device 910 in a preset lighting area. The receiver 1110includes an optical sensor such as a lens and a photodiode, and receivesa visible light signal from the lighting device 910 using the opticalsensor.

The extractor 1120 extracts visible light communication data from thereceived visible light signal. The extractor 1120 converts receivedanalog information into digital data (ADC), and restores the visiblelight communication data transmitted by the lighting device 910 bydecoding the converted digital data.

The controller 1130 selectively calculates position information aboutthe lighting device 910 based on the restored visible lightcommunication data. The controller 1130 checks whether or not theposition of the lighting device 910 is registered in the server 930based on the related information about the lighting device 910 includedin the visible light communication data, and selectively calculates theposition information about the lighting device 910 depending on theresult of the checking. The lighting device 910 may selectively transmitthe lighting device identifier to the terminal 920 together with thevisible light communication data depending on whether the position ofthe lighting device 910 is registered in the server 930. In this case,the controller 1130 checks whether unique identification informationcorresponding to the lighting device 910 is included in the relatedinformation about the lighting device 910, and performs a procedure ofregistering the position of the lighting device 910 depending on theresult of the checking.

In another embodiment, the lighting device 910 may transmit the lightingdevice identifier and information about whether the position of thelighting device 910 is registered to the terminal 920 together with thevisible light communication data. In this case, the controller 1130checks whether or not the position of the lighting device 910 isregistered in the server 930 based on the information about whether ornot the position of the lighting device 910 is registered, and performsthe procedure of registering the position of the lighting device 910depending on the result of the checking.

In yet another embodiment, the lighting device 910 may transmit alighting device identifier to the terminal 920 together with the visiblelight communication data. In this case, the controller 1130 performs aprocedure of registering the position of the lighting device 910 basedon the lighting device identifier and the information about whether ornot the pre-recognized position of the lighting device 910 isregistered. To this end, the controller 1130 communicates with theserver 930, and collects, in advance, the registered lighting deviceidentifier and the information about whether or not the position of thevisible light lighting device is registered.

The controller 1130 calculates the position information about thelighting device 910 based on the lighting device identifier and thecurrent position information about the terminal 920 calculated by theposition information calculator 1140. The controller 320 generatesmatching information by matching the lighting device identifier and thecurrent position information about the terminal 920, and provides thematching information as position information about the lighting device910.

The position information calculator 1140 calculates the current positioninformation about the terminal 920 and provides the same to thecontroller 1130.

The position information calculator 1140 may include a GPS sensor tocalculate current position information about the terminal 920.

In another embodiment, the position information calculator 1140 mayinclude a motion sensor to calculate the current position informationabout the terminal 920. Here, the motion sensor is preferably anacceleration sensor or a gyro sensor, but is not limited thereto. Forexample, the motion sensor may be implemented by any sensor which iscapable of calculating the motion information about the terminal 920.

The position information calculator 1140 may calculate the informationabout the current position of the terminal 920 based on the positioninformation about at least one reference lighting device in a presetlighting area and the motion information about the terminal 920 withrespect to the position of the reference lighting device collected bythe motion sensor. To this end, the position information calculator 330receives and stores the position information about at least onereference lighting device in the preset lighting area from the server930. The conventional lighting device is preferably a lighting devicepositioned at an entrance and an exit of the preset lighting area, butis not limited thereto.

The display unit 1150 outputs an information providing screen forvisible light communication data.

The communication unit 1160 includes a wireless communication module toperform wireless communication with an external device. Thecommunication unit 1160 according to this embodiment transmits theposition information about the lighting device 910 calculated by thecontroller 1130 to the lighting device 920 or the server 930. Finally,the sever 930 registers the position of the lighting device 910.

The power source unit 1170 provides necessary power for driving theterminal 920.

FIG. 12 is a flowchart illustrating a method for performingcommissioning by a lighting device according to another embodiment ofthe present disclosure.

The lighting device 910 receives the visible light communication datafrom the server 930 using a communication module (S1202). The visiblelight communication data includes information about registration of thelighting device 910 in the server 930.

The lighting device 910 checks, based on the received visible lightcommunication data, whether or not the position of the lighting device910 is registered in the server 930 (S1204). The lighting device 910checks whether or not the position of the lighting device 910 isregistered in the server 930 based on the registration information aboutthe lighting device 910 included in the visible light communicationdata.

The lighting device 910 determines whether the position of the lightingdevice 910 is registered in the server 930 according to the result ofthe checking (S1206).

If the position information about the lighting device 910 is registeredin the server 930, a lighting control signal is generated based on thevisible light communication data (S1208).

If the position information about the lighting device 910 is notregistered in the server 930 as a result of the checking, the lightingdevice 910 generates a lighting control signal based on the lightingdevice identifier and the visible light communication data (S1210). Thelighting device 910 may generate a lighting control signal, consideringlighting type information in addition to the lighting device identifierand the visible light communication data.

The lighting device 910 generates a visible light signal by driving thelighting unit based on the lighting control signal (S1212).

FIG. 13 is a flowchart illustrating a method for performingcommissioning by a terminal according to another embodiment of thepresent disclosure.

The terminal 920 receives a visible light signal from at least onelighting device 910 in a preset lighting area (S1302).

The terminal 920 extracts visible light communication data from thereceived visible light signal (S1304).

The terminal 920 identifies whether or not the position of the lightingdevice 910 is registered based on the related information about thelighting device 910 included in the extracted visible lightcommunication data (S1306). If the related information about thelighting device 910 includes the lighting device identifier, theterminal 920 determines that the position of the lighting device 910 isregistered in the server 930.

If the position of the lighting device 910 is not registered in theserver 930, the terminal 920 calculates current position informationabout the terminal 920 (S1310). The terminal 920 may calculate thecurrent position information about the terminal 920 using a GPS sensoror a motion sensor.

The terminal 920 calculates position information about the lightingdevice 910 based on the lighting device identifier and the currentposition information about the terminal 920 (S1312). The terminal 920generates matching information by matching the lighting deviceidentifier and the current position information about the terminal 920,and provides the matching information as the position information aboutthe lighting device 910.

FIG. 14 is a diagram illustrating a visible light communication systemaccording to yet another embodiment of the present disclosure.

A visible light communication system 1400 includes a lighting device1410 and a terminal 1420.

The lighting device 1410 is a device that transmits data to the terminal1420 using visible light communication or wireless communication. Thelighting device 1410 generates a visible light communication signalusing a visible light communication module and transmits the same to theterminal. Visible light communication refers to a technology fortransmitting information using light in the visible light wavelengthrange that is recognizable by the eyes. In this technique, turning onand off is repeated to present data to be transmitted to the terminal.The light is repeatedly turned on and off to express data to betransmitted to the terminal. Since the lighting device 1410 repeatsturning on or off at a speed that the human optic nerve cannotrecognize, it may transmit data while maintaining the function oflighting.

The lighting device 1410 may also include a wireless communicationmodule, and may transmit and receive data to and from the terminal 1420using wireless communication. Wireless communication refers to acommunication technology for transmitting information to a remote placeusing radio waves without a connection by wires. Examples of thistechnology include Bluetooth, RFID (Radio Frequency Identification),IrDA (Infrared Data Association), UWB (Ultra-Wide Band), ZigBee, DLNA(Digital Living Network Alliance), WLAN (Wireless LAN), Wi-Fi, WiBro(Wireless broadband), WIMAX (World Interoperability for MicrowaveAccess), HSDPA (High Speed Downlink Packet Access), and LTE/LTE-A (LongTerm Evolution/LTE-Advanced). The lighting device 1410 may beimplemented using a light emitting diode (LED), but is not limitedthereto. The LED may be replaced with any device that emits visiblelight such as fluorescent light or visible light laser.

The lighting device 1410 generates a combined signal. An electricalsignal corresponding to data to be transmitted using visible lightcommunication (hereinafter referred to as “visible light communicationelectrical signal”) is transmitted to the visible light communicationmodule, and the visible light communication module transmits data to theterminal through visible light communication according to the visiblelight communication electrical signal. Similarly, an electrical signalcorresponding to data to be transmitted using wireless communication(hereinafter referred to as “wireless communication electrical signal”)is transmitted to the wireless communication module, and the wirelesscommunication module transmits data to the terminal through wirelesscommunication according to the wireless communication electrical signal.The combined signal refers to a signal containing a combination of avisible light communication electrical signal and a wirelesscommunication electrical signal. The wireless communication electricalsignal may be a pulse modulated signal, e.g., a signal subjected topulse width modulation (PWM), pulse amplitude modulation (PAM), or pulseposition modulation (PPM), but is not limited thereto. The wirelesscommunication electrical signal may be a velocity-modulated signal or aphase-modulated signal. The wireless communication electrical signalpresents attribute information about the light using the pulse width,the pulse amplitude, and the like. Hereinafter, for simplicity, it isassumed that the wireless communication electrical signal is apulse-width modulated signal. After pairing is completed, the lightingdevice 1410 generates a combined signal including data to betransmitted, and transmits the data to the terminal 1420 using wirelesscommunication or visible light communication. Since only one of thevisible light communication electrical signal and the wirelesscommunication electrical signal can be generated, the conventionallighting device has inconvenience as it is selectively operated as alight or a communication device. In addition, in order to simultaneouslyoperate as a light and as a communication device, the conventionallighting device is required to include both a module for generating avisible light communication electrical signal and a module forgenerating a wireless communication electrical signal. In contrast, thelighting device 1410 according to an embodiment of the presentdisclosure generates a combined signal, and thus only needs to include acombined signal generation module rather than including all modules forgenerating the respective types of electrical signals. Further, sincethe combined signal including the respective electrical signals istransmitted to each communication module, and each communication moduleonly needs to transmit data in accordance with the combined signal,there is no need to selectively operate the lighting device 1410 as alight or as a communication device.

For wireless communication with the terminal 1420, the lighting device1410 attempts pairing. After being paired, the lighting device 1410transmits and receives data using the wireless communication module. Thelighting device 1410 transmits the lighting device identifier to theterminal 1420 through visible light communication, and pairing forwireless communication is established between the lighting device 1410and the terminal 1420 as the lighting device receives wirelesscommunication configuration information about the terminal 1420 from theterminal. The wireless communication configuration information about theterminal refers to information for identifying wireless communicationemployed by the terminal and includes a MAC address for wirelesscommunication. After pairing is completed, the lighting device 1410transmits and receives data to and from the terminal 1420 using thewireless communication module. The lighting device 1410 transmits, tothe terminal 1420, a combined signal including the data to betransmitted, using the wireless communication module.

The terminal 1420 is a device that receives data transmitted from thelighting device 1410 through visible light communication or wirelesscommunication and transmits data to the lighting device 1410 throughwireless communication. The terminal 1420 has a built-in or externalvisible light receiving module, and receives a visible lightcommunication signal from the lighting device 1410 using the visiblelight receiving module and converts the same into an electrical signal.The visible light receiving module may be implemented as a camera, aphotodiode, or the like, but is not limited thereto. The visible lightreceiving module may be replaced with any module capable of receivingvisible light.

The terminal 1420 receives the data transmitted through visible lightcommunication or wireless communication according to the combined signalfrom the lighting device 1410 and extracts a desired signal therefrom.The terminal 1420 receives data transmitted through visible lightcommunication according to the combined signal, using the visible lightreceiving module. The terminal 1420 extracts data of only the visiblelight communication electrical signal from the combined signal using afilter. In addition, the terminal 1420 receives data transmitted throughwireless communication according to the combined signal, using awireless communication module. The terminal 1420 extracts data of onlythe wireless communication signal from the combined signal, using afilter.

The terminal 1420 attempts pairing for wireless communication with thelighting device 1410, and transmits and receives data through wirelesscommunication after the completion of pairing.

FIG. 15 is a block diagram of a lighting device according to yet anotherembodiment of the present disclosure.

The lighting device 1410 includes a communication unit 1510, acontroller 1520, an offset storage unit 1530, a switching unit 1540, alighting part 1550, a timer 1560, and a data storage unit 1570.

The communication unit 1510 transmits data to the terminal 1420according to the combined signal, and receives attribute informationabout the light or other data. The communication unit 1510 includes awireless communication module and transmits and receives data and thelike to and from the terminal 1420 through wireless communication usinga wireless communication module. The communication unit 1510 receivesthe attribute information about the light from the terminal 1420 or anIoT device including a lighting sensor. The attribute information aboutthe light is information on the brightness of the light, andconceptually includes luminosity, intensity of illumination, luminance,or dimming. Further, the communication unit 1510 may receive thewireless communication configuration information about the terminal 1420from the terminal 1420.

The controller 1520 generates a combined signal. A data transmissioninterval and a data non-transmission interval are present in one periodof the wireless communication electrical signal. The ratio of theseintervals depends on the type of the wireless communication electricalsignal and the standard established for each type. For example, whenZigBee communication is employed as wireless communication, there is anabout 38 ms data non-transmission interval in one period. The controller1520 combines the visible light communication electrical signal with thewireless communication electrical signal in the data non-transmissioninterval in one period of the wireless communication electrical signal.

However, the controller 1520 must consider the transfer speed of thewireless communication electrical signal and the visible lightcommunication electrical signal in combining both electrical signals.The speed of a wireless communication electrical signal is generallylower than the speed of a visible light communication electrical signal,although it depends on the standard established for the wirelesselectrical signal. If the switching limit speed of the switching unit1540 in the lighting device 1410 is higher than the speed of the visiblelight communication electrical signal, there is no problem even if thetwo electrical signals are simply combined. However, if the switchinglimit speed of the switching unit 1540 is lower than the speed of thevisible light communication electrical signal, it is difficult togenerate a combined signal. Since most lighting devices control theattributes of the lighting through wireless communication, they haveonly switching units sufficient to satisfy the speed of the wirelesscommunication electrical signal. Therefore, if a lighting device havinga typical switching unit merely combines the two signals, a problem asshown in FIG. 16(a) arises.

FIG. 16(a) is a graph depicting a waveform of a signal radiated from aconventional lighting device.

The graph shown in FIG. 16 (a) shows a waveform of an electrical signalgenerated when a conventional lighting device simply combines a wirelesscommunication electrical signal and a visible light communicationelectrical signal. The combined electrical signal is divided into aninterval 1610 in which a wireless communication electrical signal ispresent and an interval 1620 in which a visible light communicationelectrical signal is present, and the intervals appear sequentially. Inthe visible light communication electrical signal interval 1620, theamplitude of the visible light communication electrical signal beforebeing subjected to combination is set to the same amplitude as theamplitude of the wireless communication electrical signal. However, whenthe switching limit speed of the switching unit does not satisfy thespeed of the visible light communication electrical signal, noise 1630is produced in the interval 1620 in which the visible lightcommunication electrical signal is present, as shown in the figure.Accordingly, when the conventional lighting device adds data to thevisible light communication electrical signal in the combined signal,there is a concern that the data to be transmitted may not be completelytransmitted to the terminal.

In order to prevent such a problem while using a typical switching unitwhich cannot maintain the speed of visible light communication, alighting device according to an embodiment of the present disclosureemploys a velocity offset. The wireless communication electrical signaland the visible light communication electrical signal are not simplycombined without any manipulation, but the switching speed of thewireless communication electrical signal is set to a specific velocityoffset, and the visible light communication electrical signal iscombined with a wireless communication electrical signal having theswitching speed of the specific offset value. As the wirelesscommunication electrical signal having the switching speed of thespecific offset value is combined with the visible light communicationelectrical signal, no noise is generated in the visible lightcommunication electrical signal. The controller 1520 determines thevelocity offset value of the wireless communication electrical signal.The pulse width or amplitude of the wireless communication electricalsignal varies with time depending on the attribute information about thelight received by the communication unit 1510. For example, the width ofa pulse of a wireless communication electrical signal varies with changein dimming of the light. To determine a velocity offset suitable for thewireless communication electrical signal that varies with time, thecontroller 1520 determines a velocity offset corresponding to theattribute information about the light reflected in the current wirelesscommunication electrical signal among the velocity offsets stored in theoffset storage unit 1530. For example, if dimming of the lighting is setto 30% and this setting is reflected in the wireless communicationelectrical signal, the controller 1520 may determine the velocity offsetof the wireless communication electrical signal to be 250 kbit/s. Ifdimming of the lighting is set to 35% and this setting is reflected inthe wireless communication electrical signal, the controller 1520 maydetermine the velocity offset of the wireless communication electricalsignal as 300 kbit/s.

When generating a combined signal to be transmitted to the terminal 1420for the first time, the controller 1520 generates a combined signalincluding a visible light communication electrical signal containing alighting device identifier. The lighting device 1410 and the terminal1420 are not paired for wireless communication before the lightingdevice 1410 transmits a combined signal to the terminal 1420.Accordingly, the controller 1520 generates a combined signal includingthe lighting device identifier in the visible light communicationelectrical signal to allow the terminal 1420 to receive the lightingdevice identifier for pairing. The terminal 1420 may receive thelighting device identifier included in the combined signal and identifyand register the lighting device 1410 and may attempt pairing forwireless communication. For pairing, the terminal 1420 transmits theconfiguration information about the wireless communication used by theterminal to the lighting device 1410. When the communication unit 1510receives the configuration information about the wireless communication,the controller 1520 performs a control operation to store the wirelesscommunication configuration information in the data storage unit 1570.

The offset storage unit 1530 stores the velocity offset of the wirelesscommunication electrical signal. As described above, if the wirelesscommunication electrical signal varies according to the attributeinformation about the light, a velocity offset value suitable for thechanged wireless communication electrical signal is required in order toprevent the noise from being generated in the visible lightcommunication electrical signal. The offset storage unit 1530 stores avelocity offset of the wireless communication electrical signalcorresponding to the attribute information about each light within apreset range. For example, suppose that the attribute information aboutlighting is dimming of the light, and the preset range is from 30% to70% of dimming. The offset storage unit 1530 stores a velocity offsetcorresponding to each dimming value within the range of 30% to 70% ofdimming of the lighting. The offset storage unit 1530 may store 250kbit/s as the velocity offset when the dimming of the lighting is 30%,and 300 kbit/s as the velocity offset when the dimming of the lightingis 35%. The controller 1520 may generate a combined signal and maydetermine, from the offset storage unit 1530, a velocity offsetcorresponding to the attribute information about the light included inthe wireless communication electrical signal in the combined signal.

The switching unit 1540 receives the combined signal and the velocityoffset from the controller 1520, and performs switching so as to conformto the combined signal and the velocity offset. In switching thewireless communication electrical signal in the combined signal, theswitching unit 1540 determines the switching speed in consideration ofthe velocity offset received from the controller 1520. Once theswitching unit 1540 switches the combined signal in consideration of thevelocity offset, a signal having a waveform as illustrated in FIG. 16(b)is output.

FIG. 16(b) is a graph depicting a waveform of a signal radiated from alighting device according to yet another embodiment of the presentdisclosure.

The switching unit 1540 applies the velocity offset to the interval 1640in which the wireless communication electrical signal is present in thecombined signal. Accordingly, unlike the waveform shown in FIG. 16A,noise is not generated in the interval 1650 in which the visible lightcommunication electrical signal is present in the combined signal.

The lighting part 1550 transmits data to the terminal according toswitching of the switching unit 1540 using visible light communication.In transmitting the data according to the combined signal throughvisible light communication, the lighting part 1550 does not specify aterminal, but transmits the combined signal to all the terminals withinthe range reached by the visible light signal of the lighting part 1550.

The timer 1560 provides the controller 1520 with the timing of combiningthe wireless communication electrical signal with the visible lightcommunication electrical signal. For the wireless communicationelectrical signal, the data transmission interval and the datanon-transmission interval are usually set according to the standard. Thecombining timing is intended to allow the controller 1520 to accuratelycombine the visible light communication electrical signal in thedetermined interval. The timer 1560 provides the combining timing, andthe controller 1520 combines the visible light communication electricalsignal with the wireless communication electrical signal according tothe received combining timing.

The data storage unit 1570 stores configuration information about thewireless communication. Upon receiving the combined signal, the terminal1420 transmits the configuration information about the wirelesscommunication used by the terminal 1420 to the communication unit 1510to allow pairing. When the communication unit 1510 receives theconfiguration information about the wireless communication, the datastorage unit 1570 stores the configuration information about thewireless communication used by the terminal 1420 under control of thecontroller 1520.

FIG. 17 is a block diagram of a terminal according to yet anotherembodiment of the present disclosure.

The terminal 1420 includes a visible light receiver 1710, a first filter1720, a communication unit 1730, a second filter 1740, and a controller1750.

The visible light receiver 1710 receives data corresponding to thecombined signal from the lighting device 1410 using the visible lightreceiving module. After receiving the data transmitted through visiblelight communication according to the combined signal, the visible lightreceiver 1710 may convert the same into an electrical signal, andprovide the electrical signal to the first filter 1720.

The first filter 1720 filters out data corresponding to the wirelesscommunication electrical signal of the combined signal among the datareceived by the visible light receiver 1710. The first filter 1720removes data corresponding to the wireless communication electricalsignal because the necessary data of the received data is datacorresponding to the visible light communication electrical signal. Atthis time, the first filter 1720 may remove the wireless communicationelectrical signal from the combined signal using a difference in speedbetween the visible light communication electrical signal and thewireless communication electrical signal, but embodiments are notlimited thereto.

Using the wireless communication module, the communication unit 1730receives data according to the combined signal from the lighting device1410 or transmits a signal or data to the lighting device 1410.

The second filter 1740 filters out data corresponding to the visiblelight communication electrical signal of the combined signal among thedata received by the communication unit 1730. The second filter 1740removes the data corresponding to the visible light communicationelectrical signal from the combined signal because the necessary dataamong the received data is data corresponding to the wirelesscommunication electrical signal.

The controller 1750 checks the data included in the combined signal thathas been filtered, and controls the communication unit 1730 to transmitthe data to the lighting device 1410. The controller 1750 receives anelectrical signal including the lighting device identifier from thefirst filter 1720. By checking the lighting device identifier, thecontroller 1750 identifies the lighting device 1410 that transmitted thecombined signal and registers the lighting device 1410. The controller1750 controls a message for permitting joining the network used by theterminal 1420 to be transmitted to the registered lighting device 1410.The controller 1750 controls the communication unit 1730 to transmit anetwork join permission message to the lighting device 1410 in order toestablish pairing between the terminal 1420 and the lighting device1410. Thereafter, when the communication unit 1730 receives a networkjoin message from the lighting device 1410, the controller 1750 controlsthe communication unit 1710 to transmit the configuration informationabout the wireless communication used by the terminal 1420 to thelighting device 1410 to allow pairing. As the communication unit 1730transmits the wireless communication configuration information undercontrol of the controller 1750, pairing between the terminal 1420 andthe lighting device 1410 is completed.

The controller 1750 may control the communication unit 1730 to transmitthe attribute information about the light to the lighting device 1410.The lighting device 1410 reflects the received attribute informationabout the light in the wireless communication signal.

FIG. 18 is a timing chart illustrating a process of pairing a lightingdevice and a terminal according to yet another embodiment of the presentdisclosure.

Before pairing is performed, the lighting device 1410 transmits alighting device identifier to the terminal 1420 (S1810). The lightingdevice 1410 generates a combined signal by including the lighting deviceidentifier in the visible light communication electrical signal, andtransmits the combined signal to the terminal 1420.

The terminal 1420 transmits a network join permission message to thelighting device 1410 (S1820). More specifically, upon receiving datafrom the lighting device 1410 according to the combined signal includingthe lighting device identifier, the terminal 1420 registers the lightingdevice 1410 corresponding to the lighting device identifier. Afterregistration, the terminal 1420 transmits a network join permissionmessage to the lighting device 1410 to establish pairing between theterminal 1420 and the lighting device 1410.

Upon receiving the network join permission message from the terminal1420, the lighting device 1410 transmits a network join message to theterminal 1420 (S1830).

Upon receiving the network join message from the lighting device 1410,the terminal 1420 transmits configuration information about the wirelesscommunication of the terminal to the lighting device 1410 (S1840).

Pairing for wireless communication between the lighting device 1410 andthe terminal 1420 is completed (S1850).

FIG. 19 is a flowchart illustrating an operation of a lighting deviceaccording to yet another embodiment of the present disclosure.

The communication unit 1510 of the lighting device 1410 receives theattribute information about the light from the terminal 1420 or an IoTdevice (not shown) including a lighting sensor (S1910).

The controller 1520 generates a combined signal reflecting the attributeinformation about the light (S1920). The wireless communicationelectrical signal reflects the attribute information about the lightusing pulse width, pulse amplitude, or the like, and adds data to betransmitted to the terminal 1420 after pairing is completed.

The controller 1520 determines a velocity offset for the attributeinformation about the light (S1930). The offset storage unit 1530 of thelighting device 1410 keeps a velocity offset for the attributeinformation about each light stored therein within a preset range. Thecontroller 1520 determines a velocity offset corresponding to thereceived attribute information about the light from the offset storageunit 1530.

The controller 1520 determines the velocity offset to allow theswitching unit 1540 to adjust the speed of the wireless communicationelectrical signal in the combined signal according to the velocityoffset, and transmits the velocity offset along with the combined signalto the switching unit 240 (S1940). If the speed of the wirelesscommunication electrical signal in the combined signal is adjustedaccording to the velocity offset, noise generation is prevented even iftwo electrical signals having different speeds are combined.

The lighting part 1550 or the communication unit 1510 transmits thecombined signal to the terminal 1420 using visible light communicationor wireless communication (S1950).

Steps are described to be sequentially performed in FIGS. 7, 8, 12, 13and 19 as a mere example for describing the technical idea of someembodiments, although one of ordinary skill in the pertinent art wouldappreciate that various modifications, additions and substitutions arepossible by performing the sequences shown in FIGS. 7, 8, 12, 13 and 19in a different order or at least one of steps in parallel withoutdeparting from the idea and scope of the embodiments, and hence theexamples shown in FIGS. 7, 8, 12, 13 and 19 are not limited to thechronological order.

The steps shown in FIGS. 7, 8, 12, 13 and 19 can be implemented as acomputer program, and can be recorded on a non-transitorycomputer-readable medium. The computer-readable recording mediumincludes any type of recording device on which data that can be read bya computer system are recordable. Examples of the computer-readablerecording medium include a magnetic storage medium (e.g., a floppy disk,a hard disk, a ROM, USB memory, etc.), an optically readable medium(e.g., a CD-ROM, DVD, Blue-ray, etc.) and carrier waves (e.g.,transmission through the Internet). Further, an examplecomputer-readable recording medium has computer-readable codes that canbe stored and executed in a distributed mode in computer systemsconnected via a network.

As described above, according to one aspect of the embodiments, as aterminal transmits data to a light using wireless communication, thelighting device is allowed to collectively register the lighting deviceand the terminal, and thus the process of registering a visible lightcommunication device with a server may be simplified.

According to another aspect of the embodiments, the visible lightcommunication system selectively transmits an identifier of a lightingdevice during visible light communication and the position registrationprocedure for the lighting device is automatically performed basedthereon. Accordingly, the position of the lighting device may be easilyacquired, and the visible light communication system may be configuredmore efficiently.

According to another aspect of the embodiments, since the lightingdevice provides a visible light communication signal and a wirelesscommunication signal by combining the same, a need to selectivelyperform the operation of transmitting the visible light communicationsignal and the operation of transmitting the wireless communicationsignal may be eliminated, and accordingly the corresponding flickeringeffect may be prevented.

Although exemplary embodiments of the present disclosure have beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the idea and scope of the claimedinvention. Exemplary embodiments of the present disclosure have beendescribed for the sake of brevity and clarity. Accordingly, one ofordinary skill would understand the scope of the disclosure is notlimited by the explicitly described above embodiments but is inclusiveof the claims and equivalents thereof.

What is claimed is:
 1. A method performed by a lighting devicecommunicatively connected to a service server, the method comprising:receiving a lighting search signal from the service server; in responseto the lighting search signal, emitting visible light containing aterminal search signal to discover at least one terminal within anillumination coverage of the lighting device; receiving a terminalregistration signal including a terminal identifier from said at leastone terminal, wherein the terminal registration signal is created atsaid at least one terminal when said at least one terminal receives thevisible light containing the terminal search signal; and transmitting alighting registration signal to the service server, the lightingregistration signal including the terminal identifier and a lightingidentifier for identifying the lighting device, and thereby enabling theservice server to register the lighting device together with said atleast one terminal.
 2. The method of claim 1, the method furthercomprising: receiving, from the service server, at least one terminalidentifier for identifying terminal that has applied for a certainservice; and when the terminal identifier included in the terminalregistration signal matches said at least one terminal identifierreceived from the service server, transmitting the lighting registrationsignal to the service server.
 3. The method of claim 1, the methodfurther comprising: receiving, from the service server, at least oneservice identifier that identifies at least one certain service, whereinthe terminal search signal includes said at least one service identifierto thereby discover at least one terminal which is located in theillumination coverage and has applied for said at least one certainservice.
 4. The method of claim 1, wherein the terminal registrationsignal further includes a service identifier, and wherein the methodfurther comprises: receiving, from the service server, at least oneservice identifier that identifies at least one certain service and atleast one terminal identifier that identifies at least one terminal hasapplied for said at least one certain service; comparing the serviceidentifier included in the terminal registration signal with said atleast one service identifier received from the service server; and whenboth the terminal identifier and the service identifier contained in theterminal registration signal match said at least one service identifierand said at least one terminal identifier, transmitting the lightingregistration signal to the service server.
 5. The method of claim 1,wherein the terminal search signal includes control information forcoordinating the timing at which said at least one terminal transmitsthe terminal registration signal to the lighting device.
 6. The methodof claim 1, wherein the terminal registration signal is received fromthe terminal via a short-range wireless communication channel.
 7. Themethod of claim 6, wherein the terminal search signal includes thelighting identifier for identifying the lighting device, andestablishment of the short-range wireless communication channel isinitiated by the terminal based on the lighting identifier.
 8. Themethod of claim 1, wherein the terminal search signal further includescontrol information for coordinating the timing at which the terminaltransmits the terminal registration signal to the lighting device, andwherein the method further comprises determining a timing to transmitthe terminal registration signal to the lighting device.
 9. A methodperformed by a terminal communicatively connected to a service server,the method comprising: receiving, from the service server, at least oneservice identifier that identifies at least one certain service providedby the service server; receiving visible light emitted from a lightingdevice communicatively connected to the service server, the visiblelight containing a terminal search signal which includes a serviceidentifier assigned to the lighting device; comparing the serviceidentifier included in the terminal search signal with said at least oneservice identifier received from the service server; and when theservice identifier included in the terminal search signal matches saidat least one service identifier received from the service server,transmitting, to the lighting device, a terminal registration signalincluding a terminal identifier for identifying the terminal.
 10. Themethod of claim 1, wherein the terminal registration signal istransmitted to the lighting device via a short-range wirelesscommunication channel.
 11. The method of claim 10, wherein the terminalsearch signal further includes a lighting identifier for identifying thelighting device, and establishment of the short-range wirelesscommunication channel is initiated by the terminal based on the lightingidentifier.